The present invention relates to an antistatic agent for vinyl chloride-based resins, which is superior in terms of antistatic properties, a vinyl chloride-based resin composition containing this antistatic agent, and a method for manufacturing this antistatic composition.
Vinyl chloride-based resins are superior in terms of moldability, and can be utilized in various types of molding methods. Furthermore, the molded articles obtained from such resins are superior in terms of flame retarding properties, weatherability, water resistance, chemical resistance and the like, and can be used in a broad range of applications, e.g., construction materials such as pipes, couplings, corrugated boards, films and sheets, window sashes and the like.
However, the surface resistivity of vinyl chloride-based resins is so high as to be 1013 to 1014 ohms, so that the surfaces of such resins tend to become charged with static electricity when rubbed; furthermore, once these resins have been charged, the charges tend not to leak from the surface, so that various problems arise. Examples of such problems include the following: for instance, in cases where vinyl chloride-based resins are used as base materials, the flowability of the resin may decrease and aggregate form blocks may be formed so that problems in conveying work such as clogging of pipes and bridging of hoppers occur. Furthermore, problems in molding and working may occur, such as obstruction of the uniform mixing of the overall composition containing such resins, and there may also be problems in terms of safety such as the triggering of ignition or explosion, and problems in terms of external appearance such as deterioration of the external appearance of the product due to the adsorption of dirt and dust.
Furthermore, when a vinyl chloride-based resin has been charged with static electricity, the bulk density drops, so that there are also problems from the standpoint of metering errors in terms of weight when a specified volume is metered.
Usually, a method in which antistatic agents are added to a vinyl chloride-based resin is used in order to solve such problems caused by static electricity in vinyl chloride-based resins. In most cases, surfactants are used as the antistatic agent.
For example, an antistatic vinyl chloride-based resin composition in which an anionic and/or nonionic surfactant, a perchlorate and a polyethylene oxide are blended with a vinyl chloride-based resin has been proposed in Japanese Patent Application Laid-Open No. 6-179789.